1. Field of the Invention
The present invention relates to single and multi-tuner television receiving techniques and apparatus generally, and more particularly, to a process and circuit that enable a user to restrict viewing of selected video image programs of an appliance equipped with either a single or a multiple number of television tuners.
2. Description of the Background Art
Recent proposed changes in federal regulations within the United States mandate that a discretionary control feature, commonly called the “V-chip” function, be incorporated into the design and construction of consumer television receiver circuits. This V-chip function allows a parent or other responsible person discretionary control to block-out television programs that the parent deems to be inappropriate for young viewers. The V-chip function may be implemented by incorporation into one or more dedicated ICs or by inclusion in a microprocessor. The proposed discretionary control feature will be encoded and transmitted to television receivers on the twenty-first (i.e., line 21) line of the 525 horizontal scanned lines that make up one frame of each picture screen. Each transmission of line 21 contains a synchronizing clock burst that is followed by data. The data contained within line 21 also contains closed captioning information to display words (i.e., descriptive text) on the television screen for hearing impaired viewers. Line 21 data further includes discretionary control data with a value representing the level of sex and violence in the corresponding video program that is currently being run. The discretionary control data is fed into the microprocessor or V-chip integrated circuit. The parent pre-sets a discretionary threshold for the television receiver. If the discretionary control data carried by line 21 is less than the discretionary threshold set for the television receiver, then the amount and degree of sex and violence in the currently running program is considered to be acceptable, and the viewer is allowed to watch the program. If the discretionary control data is greater than the discretionary threshold, then the amount and degree of sex and violence in the presently running program is considered to be unacceptable, and the video signal carried by that channel is blanked out, or otherwise made unviewable.
Appliances for watching video programs have been constructed in recent years with multiple tuners. Video appliances constructed with two or more tuners, such as television receivers coupled with video cassette recorders (i.e., a TVCR), have been proposed for example, by Sung-doug Kim in an Apparatus For Performing Programmed Recording Using Broadcast Program Data and Method Therefor In a Two-tuner System, U.S. Pat. No. 6,058,242 issued on the 2nd of May 2000. These multi-tuner video appliances are also sometimes referred to as “TV/VCR combos” by retail vendors such as Circuit City.
I have noticed however, that this type of supervisory discretionary control can be implemented out only for video receiving appliances that have a single tuner. Therefore, a viewer can watch a program that carries discretionary control data with a value that is greater than the discretionary threshold by using multiple devices or by using a device equipped with two turners, for example, a TV coupled with a video cassette recorder (e.g., a VCR or a TVCR). In further detail, if the value of the discretionary control data for a program is greater than the discretionary threshold value that has been set by the user of that video appliance, a video signal received through a TV receiving tuner is blanked out or made unviewable, whereas the same program can be recorded onto a video cassette tape through the recording tuner of the VCR. Consequently, I have found that the discretionary control function can not be easily and fully implemented with a video receiving appliance that has more than two tuners such as a TVCR, and that there is a need for a television receiving apparatus that performs the discretionary control function even when the receiving apparatus has more than two tuners such as a TVCR, and a method of restricting the viewing of selected video programs via video receiving appliances that are equipped with multiple tuners.